I'm a member of some SE sites, like SO and CSTheory. In those sites I'm an active member, I'm reading Q&A and also answering some questions or asking questions, but I think my writing is poor.

I like to write letters without thinking about grammar (like a child), but I think I'm a bad writer, because too many times my questions and answers are being edited. In fact, most of my problems are in my questions. I don't know how to ask good questions, which means I can't express my problem well (but my answers are not too bad).

I want to improve my writing, specifically when I want to ask long questions relating to my field (Computer Science). What's a good practice for this?

4 Answers
4

I commend you for wanting to improve your writing. :) You can look at how other people have edited your questions and compare the changes. For example, in your question above:

I'm a member of some SE sites, like SO and CSTheory.

You need "and" between two items in a list. You need to end a sentence with a period.

In those sites I'm an active member.

Indefinite article before the noun. You then have a string of clauses which should be separated into sentences.

I'm reading Q&A and also answering some Q or asking Q, but I think my writing is very poor.

Join the two clauses with "and."

I like to write letters without thinking about grammar (like a child), but I think I'm a very bad writer, because too many times my questions and answers are being edited.

You've written many posts (letters), so make that plural. You are referring to "child" and "writer" as generics, so use the indefinite article. Change the tense so it's not happening in the future, but describing a generic event which happens repeatedly.

You get the idea. (I also changed the title of your question because you are asking about how to improve the writing of any question, not just technical ones.)

I gave you an upvote for your question: I wish more on SO would ask it.

Good SO questions and answers are hard work. I try to improve my questions by finding and studying good questions. I think that good questions have been edited and worked over to share some attributes:

They are succinct: not too wordy or overlong.

They are free of lazy jargon and ill-used shortcut words.

They get to the point without unneeeded discursion.

They are careful to stay on the point and on topic.

They follow the rules of spelling and grammar.

Professor Strunk's advice is best, imo:

"Vigorous writing is concise. A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts.

"This requires not that the writer make all his sentences short, or that he avoid all detail and treat his subjects only in outline, but that every word tell."

Unless you are a completely fluent speaker who has spent much time thinking about grammar in the past so that it is effortless to get it correct, you will make grammatical errors unless you think about it. This will distract and confuse your readers. Other aspects of presenting a question--for example, presenting information in a clear and logical order so that a reader understands the relevant context--are also very important, but doing this well in the face of many grammatical errors is exceedingly difficult.